Competition between charging and discharging surface reactions as a mechanism for the Fermi-level pinning at semiconductor surfaces

Publisher Website
Google Scholar
Abstract
A new mechanism for the Fermi-level pinning at semiconductor surfaces is proposed. It is based on consideration of electrically active surface chemical reactions which create or destroy the surface charge. Mutual neutralization of the charging and discharging reactions leads to the Fermi-level pinning. The compensation of charge flows is caused by inversion of the conductivity type at the surface. In this case the Fermi-Level is pinned near mid-gap. The normal and anomalous kinetics of surface-barrier formation for adsorption of O, S, Cl, Al, Au, Ag, In, Ga, Mn and Sb on GaAs(110) surface are interpreted in a two-mode chemisorption model